Chromable monoazo pyrazolone dyes



Patented Mar. 15, 1949 CHROMABLE MONOAZO PYRAZOLONE DYES Adolf Krebser, Riehen, near Basel, and Peter Hindermann, Basel, Switzerland, assignors to the firm J. R. Geigy A. G., Basel, Switzerland No Drawing. Application March 24, 1943, Serial No. 480,370. In Switzerland May 16, 1942 2 Claims. (01. 260163) It has been found that valuable chromable monoazo dyestuffs are obtained by coupling 2- aminophenol-S-sulfonic acids containing in the 4-position a cycloalkyl radical or an alkyl radical with 3 to 8 carbon atoms, with pyrazolones having no free sulfonic and carboxylic acid groups.

As p-alkylated o-aminophenolsulfonic acids of the above definition, which can for example be obtained from the corresponding alkylphenols by sulfonation, nitration and subsequent reduction, there may be used for example: 2-amino-4- isopropylphenol-6-sulfonic acid, 2-amino-4-tert. butyl-phenol-G-sulfonic acid, 2-amino-4-n-butylphenol-6-sulfonic acid, 2-amino-4-tert. amylphenol-G-sulfonic acid, 2-amino-4-diisobutylphenol-6-sulfonic acid, 2-amino-4-cyclohexylphenol-6-sulfonic acid and the like.

As coupling components there may be used for example the following pyrazolones: s-methyl- -pyrazolone, 1-(2'-methylphenyl) -3-methyl-5-pyrazo1one, lphenyl-3-methyl-5-pyrazolone-3- or -4-sulfonamide, 1-(2'-chlor0pheny1) -3-methyl 5 pyrazolone, 1-(3- or 4'-chlorophenyl)-5-pyrazolone- 3-carboxylic acid ethylester, 1- (3'-chlorophenyl) 5-pyrazolone-3-carboxylic acid amide, 1-(3'- chlorophenyl) -5-pyrazolone 3 carboxylic acid butylamine and so on.

The new dyestuffs dye wool from an acid dyebath in yellow shades which, on after-chroming, are converted into red shades and which may also be obtained directly according to the one-bath chroming process. The chromed dyeings possess very good waterand light-fastness properties.

The present invention is illustrated, but not limited, by the following examples, wherein the parts are by weight.

Example 1 23.1 parts of 2-amino-4-isopropylphenol-6- sulfonic acid (prepared from 4-isopropylphenol by sulfonation, nitration and reduction, the free acid being obtained in form of a grey crystalpowder which is easily soluble in hot water) are indirectly diazotised in the usual manner. The diazonium compound is coupled with 17.9 parts of 1-phenyl-3-methyl-5-pyrazolone in a solution made alkaline by means of sodium carbonate. When the dyestufi formation is complete, the dyestufi is salted out, filtered ofi and dried. Thus a yellow-brown powder is obtained dissolving in water with yellow-orange coloration and in concentrated sulfuric acid with orange coloration. When applied from an acid dyebath it dyes wool in yellow shades which, by after-chroming, may

1phenyl-3-methyl-5-pyrazolone,

' be converted into a yellowish red of good waterand light-fastness.

The dyestufi obtained according to the same method, but by starting from 2-amino-4-tert. butylphenol-S-sulfonic acid and 1-(2-chlorophenyl) -3-methyl -5-pyrazolone, forms a red powder dissolving in water with a dark orangered coloration, in concentrated sulfuric acid with a bright yellow-orange coloration and dyeing wool, when chromed, in yellowish-red shades of good waterand light-fastness. Dyeings having the same properties can also be obtained directly according to the one-bath chroming process.

When, in the above example, the 2-amino-4- isopropylphenol-6-sulfonic acid is replaced by the 2-amino-4-tert. amylphenol-G-sulfonic acid, a dyestufi is obtained which also constitutes a red powder possessing the same properties as that obtained from Z-amino-4-tert. butylphenol-6- sulfonic acid. The appended claims are directed specifically to this preferred form of the invention.

If in this example the 1-phenyl-3-methyl-5- pyrazolone is replaced by 1-(2-methylphenyl)- 3-methyl-5-pyrazolone or by 1-(4-methylpheriyD- or 1-(2':el' dimethylphenyl)-3-methyl- 5-pyrazolone, dyestuffs having similar properties are obtained.

Example 2 245 parts of 2-amino-4-n-butylphenol-6- sulfonic acid (obtainable from 4-n-butylphenol in an analogous manner to that described in Example 1) are, as usual, indirectly diazotised and the diazonium compound so-obtained is coupled with 26.6 parts of 1-(3'-chlorophenyl)- 5-pyrazolone-3-carboxylic acid ethylester in a soda alkaline solution. After completion of the dyestuff formation the dyestuff is precipitated by means of sodium chloride, isolated and dried. When applied according to the one-bath or afterchroming process the new dyestufi dyes wool in even bluish-red shades of good milling-, pottingand light-fastness and also of good fastness properties to alkalis.

Example 3 30.1 parts of 2-amino-4-diisobutylphenol-G- sulfonic acid made from 4-diisobutylphenol by sulfonation, nitration and subsequent reduction are indirectly diazotised and the diazonium compound is then coupled With 9.8 parts of 3-methyl- E-pyrazolone in a solution which is alkaline to sodium carbonate. As soon as the formation of the dyestufi is complete, the dyestuff is worked up in the usual manner.

and light-fastness.

Further examples illustrating this invention 5 are enumerated in the following table:

When applied according to the one-bath or after-chroming process, it dyes Wool in yellowish-red shades of good Waterfonic acid with 1-pheny1-3-methy1-5 2. A process for the manufacture of chromable monoazo dyestufls which comprises coupling diazotised 2-amino-4-tert. amy1pheno1-6-su1- -pyrazo1one.

ADOLF KREBSER.

PETER HINDERMANN.

Dian-component Coupling-component Shade of the chromed dyeing 2-anzaino-4-tert. butyl-phenol-fitfsulfonic acid o .do 2-anaino-4-n-butyl-pheno1-6-sulfonic1acid o 1-phenyl-3:methy1-5-pyrazolone 2L-(3feh lorophenyl),r3-methy1-5=pyrazolone 1 phenyl-3-methyk5-py1az0l0ne 1-(3 -chloropheny1)-5myrazolone-3-carboxy1ic acid ethyleste am e. 1- (4"methy1pheny1) '-3-1i1ethy1-5-pyrazo1one n yellowish-red.

bluish-red.

yellowish-red. o.

1. The chromablemonoazo dyestufifofettie:.for-" mula we. claim is;

REFERENCES CITED f file :of" this patentzi' 30 UNITED S'IATESfP'ATENTS Number: Y Name: Date 1,'828;055:- Krzilzallarz Oct. 20,1931 b95950? Straub 1 May'22,-1934:i

The following references azu e soft: record.- :in zthe 

